uses gl,glu,glut;
var
 cr,cv:real;
 procedure display;cdecl;
 var
  x,y,t:longint;
  xx,yy,tt,xxx,yyy:real;
 begin
  glclearcolor(0,0,0,0);
  glclear(gl_color_buffer_bit);
  glcolor3f(1,1,1);
  glbegin(gl_points);
  for x:=-300 to 300 do
   for y:=-300 to 300 do
    begin
     xx:=x/300;
     yy:=y/300;
     xxx:=xx;
     yyy:=yy;
     //writeln('xx=',xx,' yy=',yy);
     for t:=1 to 10 do
      begin
       tt:=xx;
       xx:=xx*xx-yy*yy+cr;
       yy:=2*tt*yy+cv;
      end;
     //writeln('xx=',xx,' yy=',yy);
     if xx>1 then
      continue;
     if xx<-1 then
      continue;
     if yy>1 then
      continue;
     if yy<-1 then
      continue;
     glvertex2f(xxx,yyy);
    end;
  glend;
  glflush;
  glutswapbuffers;
 end;
 procedure idle;cdecl;
 begin
  //cr:=cr+0.005;
  //if cr>1 then
  // halt;
  glutpostredisplay;
  //writeln('idled');
 end;
begin
 cr:=-0.4;
 cv:=-0.6;
 glutinit(@argc,argv);
 glutinitdisplaymode(glut_double or glut_rgb);
 glutinitwindowsize(600,600);
 glutinitwindowposition(100,100);
 glutcreatewindow('x:=x^2+c');
 glutdisplayfunc(@display);
 glutidlefunc(@idle);
 glutmainloop;
end.